The invention relates to speed wrenches. More particularly, the invention relates to flex-head speed wrenches.
A long-established art exists regarding speed wrenches. A basic speed wrench includes a single forging. The forging includes a square-section drive head at a first end for engaging a square drive socket compartment of a tool (e.g., a hex or twelve-point socket). A shaft of the wrench extends coaxially from the head. At an opposite second end, an end handle is coaxial with the head. A drive handle is radially displaced from the tool axis (e.g., parallel and spaced-apart) intermediate the head and end handle.
In speed handle operation, a socket is mounted to the head and then engaged to a fastener (e.g., a bolt or nut) to be either installed or removed. A user grasps the end handle with one hand and the drive handle with the other. The grasping of the end handle combined with the engagement of the socket to the fastener form an axis of rotation substantially coincident with the end handle axis. The drive handle and its connecting portions form a lever which the user rotates with his second hand in a circular orbit about the axis of rotation to install or remove the fastener. When used to remove a tight or stuck fastener, a breaker bar is typically used to break the fastener loose. The socket may then be transferred from the breaker bar to the speed wrench to complete the removal process.
Common variations include rotatably mounted handgrip sleeves at one or both handles. Other variations include an end knob at the end handle.
Another variation is a flex-head wrench as is found in breaker bars and similar drivers. This allows the speed wrench to be used as a breaker bar and avoids the need to transfer the socket after breaking the fastener loose. In such a flex-head wrench, the drive head is pivotally mounted to the shaft for rotation about a pivot axis normal to the common axis of the shaft end portions. In known constructions, the pivot axis is essentially coplanar with the offset of the intermediate handle. In this construction, pivoting of the drive head rotates its axis out of the plane of the offset. In breaker bar operation the head is rotated so that the drive axis is normal to the shaft axis. The head is rotated back so that the drive axis is coincident with the shaft axis for speed handle operation.